Neonatal Macrosomia is an Interfering Factor for Analytes on the Colorado State Newborn Screen

2020 ◽  
Vol 105 (4) ◽  
pp. e1561-e1568
Author(s):  
Erica L Wright ◽  
Peter R Baker

Abstract Purpose Neonatal macrosomia is a known complication of maternal obesity and gestational diabetes, and it is a risk factor for obesity and diabetes in offspring. Amino acids and acylcarnitines are biomarkers for obesity in children and adults. These analytes, which are also routinely obtained on the newborn screen, have not been well-characterized in macrosomic newborns. The impact of macrosomia on rates of false-positive results in the newborn screen has also not been well-studied. We test the hypothesis that macrosomia is an interfering factor for amino acids and/or acylcarnitines on the newborn screen. Methods Newborn screening analytes determined by tandem mass spectroscopy were obtained from the Colorado Department of Public Health and Environment archives (2016–2018). This included metabolite concentrations obtained at 24–72 hours of life from newborns with birth weight 2500 to 3999 g (nonmacrosomic, n = 131 896) versus 4000 to 8000 g (macrosomic, n = 7806). Mother/infant phenotypic data were limited to information provided on the newborn screening dried blood spot card. Data were analyzed using Student t-test and chi-squared analysis. Results Macrosomic newborns had elevations in C2, C3, dicarboxylic, and long-chain acylcarnitines (specifically C16 and C18 species). C3 and C18:1 were 2 to 3 times more likely to be above predetermined state cutoffs in macrosomic versus nonmacrosomic newborns (both male and female). Main conclusions Macrosomia is an interfering factor for the analytes C3 and C18:1, leading to higher risk of false-positive results for methylmalonic/propionic acidemia and carnitine palmitoyl transferase type 2 deficiency, respectively. Analyte patterns found in macrosomic neonates correspond with similar analyte patterns in obese children and adults.

2008 ◽  
Vol 54 (3) ◽  
pp. 542-549 ◽  
Author(s):  
Devin Oglesbee ◽  
Karen A Sanders ◽  
Jean M Lacey ◽  
Mark J Magera ◽  
Bruno Casetta ◽  
...  

Abstract Background: Newborn screening for maple syrup urine disease (MSUD) relies on finding increased concentrations of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine by tandem mass spectrometry (MS/MS). d-Alloisoleucine (allo-Ile) is the only pathognomonic marker of MSUD, but it cannot be identified by existing screening methods because it is not differentiated from isobaric amino acids. Furthermore, newborns receiving total parenteral nutrition often have increased concentrations of BCAAs. To improve the specificity of newborn screening for MSUD and to reduce the number of diet-related false-positive results, we developed a LC-MS/MS method for quantifying allo-Ile. Methods: Allo-Ile and other BCAAs were extracted from a 3/16-inch dried blood spot punch with methanol/H2O, dried under nitrogen, and reconstituted into mobile phase. Quantitative LC-MS/MS analysis of allo-Ile, its isomers, and isotopically labeled internal standards was achieved within 15 min. To determine a reference interval for BCAAs including allo-Ile, we analyzed 541 dried blood spots. We also measured allo-Ile in blinded samples from 16 MSUD patients and 21 controls and compared results to an HPLC method. Results: Intra- and interassay imprecision (mean CVs) for allo-Ile, leucine, isoleucine, and valine ranged from 1.8% to 7.4%, and recovery ranged from 91% to 129%. All 16 MSUD patients were correctly identified. Conclusions: The LC-MS/MS method can reliably measure allo-Ile in dried blood spots for the diagnosis of MSUD. Applied to newborn screening as a second-tier test, it will reduce false-positive results, which produce family anxiety and increase follow-up costs. The assay also appears suitable for use in monitoring treatment of MSUD patients.


2009 ◽  
Vol 55 (9) ◽  
pp. 1615-1626 ◽  
Author(s):  
Dennis J Dietzen ◽  
Piero Rinaldo ◽  
Ronald J Whitley ◽  
William J Rhead ◽  
W Harry Hannon ◽  
...  

Abstract Background: Almost all newborns in the US are screened at birth for multiple inborn errors of metabolism using tandem mass spectrometry. Screening tests are designed to be sufficiently sensitive so that cases are not missed. The NACB recognized a need for standard guidelines for laboratory confirmation of a positive newborn screen such that all babies would benefit from equal and optimal follow-up by confirmatory testing. Methods: A committee was formed to review available data pertaining to confirmatory testing. The committee evaluated previously published guidelines, published methodological and clinical studies, clinical case reports, and expert opinion to support optimal confirmatory testing. Grading was based on guidelines adopted from criteria derived from the US Preventive Services Task Force and on the strength of recommendations and the quality of the evidence. Three primary methods of analyte measurement were evaluated for confirmatory testing including measurement of amino acids, organic acids, and carnitine esters. The committee graded the evidence for diagnostic utility of each test for the screened conditions. Results: Ample data and experience were available to make strong recommendations for the practice of analyzing amino acids, organic acids, and acylcarnitines. Likewise, strong recommendations were made for the follow-up test menu for many disorders, particularly those with highest prevalence. Fewer data exist to determine the impact of newborn screening on patient outcomes in all but a few disorders. The guidelines also provide an assessment of developing technology that will fuel a refinement of current practice and ultimate expansion of the diseases detectable by tandem mass spectrometry. Conclusions: Guidelines are provided for optimal follow-up testing for positive newborn screens using tandem mass spectrometry. The committee regards these tests as reliable and currently optimal for follow-up testing. .


Medicine ◽  
2019 ◽  
Vol 98 (40) ◽  
pp. e17451 ◽  
Author(s):  
Mari Carmen Bernal-Soriano ◽  
Lucy A. Parker ◽  
Maite López-Garrigos ◽  
Ildefonso Hernández-Aguado ◽  
Juan P. Caballero-Romeu ◽  
...  

2020 ◽  
Vol 6 (2) ◽  
pp. 27 ◽  
Author(s):  
Jane Chudleigh ◽  
Holly Chinnery

Newborn screening for cystic fibrosis has resulted in diagnosis often before symptoms are recognised, leading to benefits including reduced disease severity, decreased burden of care, and lower costs. The psychological impact of this often unsought diagnosis on the parents of seemingly well children is less well understood. The time during which the screening result is communicated to families but before the confirmatory test results are available is recognised as a period of uncertainty and it is this uncertainty that can impact most on parents. Evidence suggests this may be mitigated against by ensuring the time between communication and confirmatory testing is minimized and health professionals involved in communicating positive newborn screening results and diagnostic results for cystic fibrosis to families are knowledgeable and able to provide appropriate reassurance. This is particularly important in the case of false positive results or when the child is given a Cystic Fibrosis Screen Positive, Inconclusive Diagnosis designation. However, to date, there are no formal mechanisms in place to support health professionals undertaking this challenging role, which would enable them to meet the expectations set out in specific guidance.


2018 ◽  
Vol 56 (2) ◽  
pp. 278-284 ◽  
Author(s):  
Theresa Winter ◽  
Anja Lange ◽  
Anke Hannemann ◽  
Matthias Nauck ◽  
Cornelia Müller

Abstract Background: Newborn screening (NBS) is an established screening procedure in many countries worldwide, aiming at the early detection of inborn errors of metabolism. For decades, dried blood spots have been the standard specimen for NBS. The procedure of blood collection is well described and standardized and includes many critical pre-analytical steps. We examined the impact of contamination of some anticipated common substances on NBS results obtained from dry spot samples. This possible pre-analytical source of uncertainty has been poorly examined in the past. Methods: Capillary blood was obtained from 15 adult volunteers and applied to 10 screening filter papers per volunteer. Nine filter papers were contaminated without visible trace. The contaminants were baby diaper rash cream, baby wet wipes, disinfectant, liquid infant formula, liquid infant formula hypoallergenic (HA), ultrasonic gel, breast milk, feces, and urine. The differences between control and contaminated samples were evaluated for 45 NBS quantities. We estimated if the contaminations might lead to false-positive NBS results. Results: Eight of nine investigated contaminants significantly altered NBS analyte concentrations and potentially caused false-positive screening outcomes. A contamination with feces was most influential, affecting 24 of 45 tested analytes followed by liquid infant formula (HA) and urine, affecting 19 and 13 of 45 analytes, respectively. Conclusions: A contamination of filter paper samples can have a substantial effect on the NBS results. Our results underline the importance of good pre-analytical training to make the staff aware of the threat and ensure reliable screening results.


Author(s):  
Owen R. Baker ◽  
M. Kate Grabowski ◽  
Ronald M. Galiwango ◽  
Aminah Nalumansi ◽  
Jennifer Serwanga ◽  
...  

Background: We assessed the performance of CoronaCHEK lateral flow assay on samples from Uganda and Baltimore to determine the impact of geographic origin on assay performance. Methods: Plasma samples from SARS-CoV-2 PCR+ individuals (Uganda: 78 samples from 78 individuals and Baltimore: 266 samples from 38 individuals) and from pre-pandemic individuals (Uganda 1077 and Baltimore 532) were evaluated. Prevalence ratios (PR) were calculated to identify factors associated with a false-positive test. Results: After first positive PCR in Ugandan samples the sensitivity was: 45% (95% CI 24,68) at 0-7 days; 79% (95%CI 64,91) 8-14 days; and 76% (95%CI 50,93) >15 days. In samples from Baltimore, sensitivity was: 39% (95% CI 30, 49) 0-7 days; 86% (95% CI 79,92) 8-14 days; and 100% (95% CI 89,100) 15 days post positive PCR. The specificity of 96.5% (95% CI 97.5,95.2) in Ugandan samples was significantly lower than samples from Baltimore 99.3% (95% CI 98.1,99.8), p<0.01. In Ugandan samples, individuals with a false positive result were more likely to be male (PR 2.04, 95% CI 1.03,3.69) or individuals who had a fever more than a month prior to sample acquisition (PR 2.87, 95% CI 1.12,7.35). Conclusions: Sensitivity of the CoronaCHEK was similar in samples from Uganda and Baltimore. The specificity was significantly lower in Ugandan samples than in Baltimore samples. False positive results in Ugandan samples appear to correlate with a recent history of a febrile illness, potentially indicative of a cross-reactive immune response in individuals from East Africa.


Author(s):  
Amy Brower ◽  
Kee Chan ◽  
Michael Hartnett ◽  
Jennifer Taylor

The goal of newborn screening is to improve health outcomes by identifying and treating affected newborns. This manuscript provides an overview of a data tool to facilitate the longitudinal collection of health information on newborns diagnosed with a condition through NBS. The Newborn Screening Translational Research Network (NBSTRN) developed the Longitudinal Pediatric Data Resource (LPDR) to capture, store, analyze, visualize, and share genomic and phenotypic data over the lifespan of NBS identified newborns to facilitate understanding of genetic disease, and to assess the impact of early identification and treatment. NBSTRN developed a consensus-based process using clinical care experts to create, maintain, and evolve question and answer sets organized into common data elements (CDEs). The LPDR contains 24,172 core and disease-specific CDEs for 118 rare genetic diseases, and the CDEs are being made available through the NIH CDE Repository. The number of CDEs for each condition average of 2,200 with a range from 69 to 7,944. The LPDR is used by state NBS programs, clinical researchers, and community-based organizations. Case level, de-identified data sets are available for secondary research and data mining. The development of the LPDR for longitudinal data gathering, sharing, and analysis supports research and facilitates the translation of new discoveries into clinical practice.


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